The invention relates to an apparatus for breaking concrete pavements, and more particularly, to a pavement breaking apparatus which does not operate with a pendulum-like swinging or rocking during pavement breaking.
Pavement breaking machines use a power driver, better known as a pile-driver, mounted on a movable chassis and towed along the concrete pavement. As the machine is towed along the pavement, heavy blows of the pile-driver cause the drive shoe to impact the pavement and break off successive chunks of concrete. The broken concrete is then available to be gathered up and crushed in a portable crushing plant for recycling.
Some of the earlier pavement breaking machines have hammers which either rock or swing in a pendulum-like manner as the machine is towed forward during the breaking operation. Such swinging or rocking can cause excessive wear of a layer of cushion material located above the neck of the drive shoe received within the adapter opening. As the hammer rocks or swings, the neck portion of the drive shoe jams against the walls of the adapter opening containing the cushion material. This jams the drive shoe neck against the adapter so as to drive the cushion material out of the adapter opening. This is, of course, an undesirable result. It would thus be desirable to provide a pavement breaking apparatus that operates without pendulum-like swinging or rocking so as to reduce or eliminate deformation of the cushion material.
This pendulum-like swinging or rocking can also result in increased stress on the upper frame structure through torsional loading. This stress may result in the premature failure of the mast and hammer. Torsional loading may also cause the hydraulic or electric lines associated with the pavement breaking apparatus to whip back and forth. It would thus be desirable to provide a pavement breaking apparatus that operates without a pendulum-like swinging or rocking so as to eliminate torsional loading on the upper frame.
Pendulum-type drivers exert an angular-type of strike against the pavement. In other words, the strike of a pendulum-type driver is divided into a vertical force component and a horizontal force component. The presence of a horizontal force component is undesirable since it reduces the vertical force exerted on the pavement to break it. It would thus be desirable to provide a pavement breaking apparatus that operates without a pendulum-like swinging or rocking so as to transmit a substantially vertical blow to the pavement.